Transport of radio network-originated control information

ABSTRACT

In a radio access network (RAN) where information may be sent to a mobile radio unit using a shared radio channel shared by other mobile radio units, a first transport bearer is established between a first RAN node, e.g., a drift RNC, and a second RAN node, e.g., a base station, to transport data to be transmitted on the shared radio channel. A second transport bearer is established between the first and second RAN nodes to transport control information originated in the first RAN node that relates to the first transport bearer data. The first RAN node then transmits the control information over the second transport bearer to the second RAIN node. The control information might include, for example, scheduling information known to the first RAN node because the first RAN node supervises scheduling of data to be transmitted on the shared radio channel. The control information may provide to the mobile radio unit information needed to decode the data transmitted on the shared radio channel. Such needed information might include, for example, a frame identifier, a specific radio resource like a spreading code, and/or an indication of how different radio resources associated with different connections are multiplexed on the shared radio channel. In one example, non-limiting embodiment, the control information includes transport format indication information such as transmit format combination indicator (TFCI) information employed in third generation Universal Mobile Telephone Systems (UMTS) in accordance with the 3GPP specification.

RELATED APPLICATIONS

This application claims priority from commonly-assigned U.S. ProvisionalPatent Application Ser. Nos. 60/190,097 and 60/191,499, filed Mar. 20,2000 and Mar. 23, 2000, respectively, the entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to radio access, more specifically, to howcertain control information communicated to a mobile radio terminal canbe efficiently transported in a Radio Access Network (RAN).

SUMMARY OF THE INVENTION

In a radio access network (RAN) where information may be sent to amobile radio unit using a radio channel shared by other mobile radiounits, a first transport bearer is established between a first RAN nodeand a second RAN node to transport data ultimately to be transmitted onthe shared radio channel. A second transport bearer is establishedbetween the first and second RAN nodes to transport control informationoriginated in the first RAN node that relates to the first transportbearer data. The first RAN node then transmits the control informationover the second transport bearer to the second RAN node.

The control information might include, for example, information known tothe first RAN node because the first RAN node supervises scheduling ofdata to be transmitted on the shared radio channel. The controlinformation may provide the mobile radio unit with information needed todecode the data transmitted on the shared radio channel. Such neededinformation might include a frame identifier, a specific radio resourcelike a spreading code in a CDMA type of communication system, and/or anindication of how different radio resources are multiplexed on theshared radio channel. In one example, non-limiting embodiment, thecontrol information includes transport format indication informationsuch as transmit format indicator (TFI) and/or transmit formatcombination indicator (TFCI) information employed in third generation(3G) Universal Mobile Telephone Systems (UMTS) systems in accordancewith the 3GPP specification.

In a preferred, example embodiment, the first RAN node is a drift radionetwork controller (DRNC), and the second RAN node is a base station(BS). A third transport bearer may be established to transport dedicatedradio channel data and dedicated radio channel control informationthrough the RAN for transmission to a mobile radio unit on a dedicatedradio channel. This third transport bearer may be established by aserving radio network controller (SRNC) working in conjunction with theDRNC to support the connection with the mobile radio unit.

In one example implementation of the present invention, acomputer-generated data signal, (e.g., generated in a computer in theDRNC), is transported on a separate transport bearer between the DRNCand the base station having a particular format. A frame number fieldincludes a specific frame number identifying a frame on the shared radiochannel. A transport format indicator field includes informationrelating to a particular radio channel resource in the correspondingframe. In one example implementation, the transport format indicatorfield includes an index to a transport format table previously stored inthe mobile radio unit. In other words, the index addresses particularentries in the look-up table so the mobile can retrieve certaininformation that will allow it to receive and decode informationintended for that mobile radio unit on the shared radio channel. Forexample, since the DRNC is in charge of scheduling how data ismultiplexed in a frame on the shared radio channel and allocatingparticular radio resources, such as channelization codes and associatedspreading factors, the DRNC can convey to the mobile radio, using thetransport format indicator, these types of specific details to allow themobile radio unit to decode information sent over the shared radiochannel.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features, and advantages of the invention will be apparentfrom the following description of the preferred but non-limiting exampleembodiment described in conjunction with the following drawings. Thedrawings are not necessarily to scale or comprehensive, emphasis insteadbeing placed upon illustrating the principles of the invention.

FIG. 1 is a function block diagram of a radio communications system inwhich the present invention may be employed;

FIG. 2 is an example transport format indicator (TFI) signaling message;

FIG. 3 is an example radio access network architecture in which certaincontrol information (Like TFI and/or TFCI messages) to be communicatedto a mobile radio terminal is transported in the radio access networkarchitecture;

FIG. 4 shows an example embodiment of the present invention in which atransport format indicator originated in a DRNC is communicated from theDRNC to a base station over a separate transport bearer;

FIG. 5 is a flowchart diagram illustrating procedures in accordance withone example implementation of the present invention;

FIG. 6 is an example signaling procedure for setting up a separatetransport bearer between a DRNC and a base station for communicatingDRNC-originated control information; and

FIG. 7 shows an example of implementation of the invention in adifferently configured RAN.

DESCRIPTION OF THE FIGURES

In the following description, for purposes of explanation and notlimitation, details are set forth pertaining to a specific RANarchitecture, having certain interfaces, signaling, and messages, inorder to provide an understanding of the present invention. However, itwill be apparent to one skilled in the art that the present inventionmay be practiced in other implementations, embodiments, and contextsthat depart from these specific details.

In some instances, detailed descriptions of well-known methods,interfaces, devices, and signaling techniques are omitted so as not toobscure the description of the present invention with unnecessarydetail. Moreover, individual function blocks are shown in some of thefigures. Those skilled in the art will appreciate that the functions maybe implemented using individual hardware circuits, using softwarefunctioning in conjunction with a suitably programmed digitalmicroprocessor or general purpose computer, using an applicationspecific integrated circuit (ASIC), and/or using one or more digitalsignal processors (DSPs).

The architecture of an example Radio Access Network (RAN) 13, theinterfaces between nodes in the RAN 13, and the physical channels on theradio interface are now described with reference to the radiocommunications system 10 shown in FIG. 1. User Equipment (UE) 22, suchas a mobile or fixed radio terminal, is used by a subscriber to accessservices offered by one or more core networks (CN) 12 (only one isshown). Examples of core networks include the PSTN, the ISDN, theInternet, other mobile networks, etc. Core networks may be coupled tothe radio access network 13 through circuit-switched and/orpacket-switched core network service nodes like Mobile Switching Center(MSC) (not shown) or a Serving GPRS Support Node (SGSN) (not shown). Theradio access network 13 typically includes plural Radio NetworkControllers (RNCs) 14, 16. Each RNC controls radio connectivity withmobile terminals within a geographical area, e.g., one or more cells,byway of one or more base stations (BS) 18, 20.

For each connection between a UE mobile terminal 30 and a core networknode 12, an RNC may perform one of two roles. As a Serving RNC (SRNC)18, the RNC controls the connection with the mobile terminal within theRAN. Sometimes, while a connection is active, the mobile terminal movesto a geographical area controlled by another RNC. This other RNC viawhich the connection is routed to the mobile terminal is called a DriftRNC (DRNC) 16. In the DRNC role, the RNC supports the SRNC by supplyingradio resources controlled by the DRNC that are needed to support theconnection with the mobile terminal. The DRNC is connected to the SRNCthrough a logical interface labeled Iur. Although there is only oneSRNC, there may be more than one DRNC involved in a mobile terminal-CNconnection, depending on any movement of the mobile terminal and radioenvironment conditions.

A Base Station (BS) node (18, 20), (sometimes called a “Node B”),provides UE radio connectivity in one or more cells. Each cell covers alimited geographical area. A base station is coupled to and controlledby a Controlling RNC (CRNC). A CRNC can be an SRNC or a DRNC. The CRNCperforms admission control for all the resources of the base stations itis controlling. In addition, the CRNC performs the scheduling of commonand shared physical channels (as described below) on the radio interfacefor these BSs. In FIG. 1, the RNC 14 labeled “SRNC” is the CRNC for basestation (BS1) 18. The RNC 16 labeled “DRNC” is the CRNC for base station(BS2) 20. A base station is connected to its CRNC through a logical Iubinterface.

User data is transported on logical “transport bearers” over the Iub/Iurinterfaces between the different nodes in the RAN. A transport bearertypically transports one transport channel including user datainformation (an information stream), and possibly also controlinformation like cyclic redundancy check (CRC), bit error rate (BER),transport format indicators like TFIs and/or TFCIs (described below),etc. Depending on the transport network used, these logical transportbearers may, for example, be mapped to actual ATM Adaptation Layer 2(AAL2) transport connections (in the case of an ATM-based transportnetwork) or User Data Protocol (UDP) transport connections (in the caseof an IP-based transport network).

The radio interface may include two groups of physical radio channels:(1) dedicated physical channels (referred to as DCH in the 3GPPspecification) and (2) shared physical channels (referred to as DSCH inthe 3GPP specification). Dedicated physical channels may be used fortransporting information between a single UE terminal and a core networkand are not shared or used by other mobile terminals. A shared physicalchannel may be used by multiple UE terminals, e.g., using a multiplexingscheme such as code or time division multiplexing. One or more transportbearers are mapped to a physical radio channel.

When a DRNC provides resources for a mobile terminal-core network (CN)connection, there are different DRNC control functions for dedicatedtypes of physical channels and for shared types of physical channels.For dedicated physical channels, the DRNC is involved in admissioncontrol because it must commit DRNC resources, (e.g., radio resourceslike spreading codes in a CDMA type system), to support the UEterminal-CN connection. Once the DRNC commits some of the resources itcontrols to support the UE terminal-CN connection, the DRNC is notresponsible for scheduling or other supervising of the physical channelresources for that UE terminal-CN connection. Instead, thisresponsibility is handled by the SRNC. However, the DRNC may inform theSRNC of local conditions, like a congestion situation in a cell, and mayrequest the SRNC to change the information rate on the dedicatedphysical channel.

For shared physical channels, the DRNC is again involved in admissioncontrol when the mobile UE terminal-core network (CN) connection isestablished, to the extent its DRNC resources are needed to support thatconnection. After the DRNC commits its resources to support the UEterminal-CN connection, however, the DRNC must perform one or moreadditional control or supervisory functions. Because a shared physicalchannel is used by multiple UE terminals, the DRNC—not the SRNC—performsthe final scheduling of the resources on the shared physical channel.

In the downlink (DL) direction from RAN to the UE terminal, due to thelast moment resource scheduling in the DRNC, the UE terminal typicallydoes not know which shared physical channel resources, will be used bythe RAN for its UE terminal-CN connection at each moment in time, e.g.,spreading codes, frame multiplex times, etc. In order to overcome thisuncertainty, (1) the UE terminal may monitor continuously all sharedphysical channel resources to detect which resources are used for itsconnection, or (2) the RAN can inform the UE terminal about thecommon/shared resources it is using to support that UE terminalconnection at each point in time. For the second approach (2), the RANmust continuously inform the UE terminal about the shared physicalchannel resources used at each moment in time. To accomplish this, theRAN must send to the UE resource identification/allocation messages on aparallel-established, dedicated radio channel before the UE is toreceive the information on the shared radio channel.

Radio channel information streams are transported in the RAN between theSRNC and the involved BS on transport bearers over the Iub and Iurinterfaces. A transport bearer transports information related to eithera dedicated physical radio channel or a shared physical radio channel.The information carried on a transport bearer used for transportinginformation related to a dedicated physical channel passes essentiallytransparently through the DRNC. However, in diversity handoverconnections, the DRNC may perform a combining (uplink from eachBS)/splitting (downlink to each BS) functions for this informationbecause multiple base stations coupled to the DRNC are supporting the UEterminal-CN connection. If the DRNC does not need to perform suchcombining/splitting, e.g., the two BSs are under the same DRNC, the DRNCneed not manipulate the transported information in neither the uplinknor downlink direction. In this case, the DRNC functions like a conduitor relay node.

For information carried on a transport bearer relating to sharedphysical channels, the DRNC must schedule the physical radiochannel-related information received for different mobile terminals fromone (or possibly more) SRNCs, i.e., multiplex different informationstreams onto the shared radio channel at different times using differentradio resources. The goal is to optimize use of the shared physicalchannel resources on the radio interface. In addition, the DRNC mayperform a rate control function with the SRNC, i.e., the DRNC requeststhe SRNC to slow down its data transmission in order to avoid congestionon the shared physical channel.

The issue is how to get this and other kinds of control informationoriginating at the DRNC to the mobile radio so it knows when and how todecode the information sent to it on the shared radio channel. Indeed,the timing of the physical channel information transport in the RAN isimportant for successful communication over the shared channel. Forscheduling control, the information transported in the downlink islabeled with a timestamp indicating when the information needs to besent over the radio interface. The base stations may use a receive“window” when receiving data from an SRNC or a DRNC. If data is receivedwithin the window, that data can be processed and transmitted on theradio interface. If the information is received too early, the basestation may not have enough buffer capacity to temporarily store thereceived information. If the information is received too late, the basestation may not have enough time to process the received information andsend it out on the radio interface at the correct moment in time. Thesignaling on the Iub/Iur interfaces can support procedures, (e.g., atiming adjustment request message), by which the base station canrequest its CRNC (for shared physical channels) or an SRNC (fordedicated physical channels) to adjust the time at which information issent to the base station.

One way in which the identity of particular physical channel resourcesto be used, (e.g., radio resources like spreading codes), and how theseresources are to be used, (e.g., type of channel coding and codingrate), may be communicated by the RAN to the mobile terminal is throughthe use of Transport Format Indication (TFI) and/or Transport FormatCombination Indication (TFCI) control messages employed in the 3GPPspecification. The invention is not limited any specific type oftransport control message format or information. The TFI and TFCI aresimply examples.

A TFI or TFCI message may be used to describe these kinds ofcharacteristics of a dedicated physical channel (hereafter “TFI1” or“TFCI1”) as well as of a shared physical channel (hereafter “TFI2” or“TFCI2”). Again, a TFI or a TFCI is just an example of a controlmessage, and other control messages as well as other types of controlinformation may be used. Using a TFI example for purposes ofillustration only, an SRNC determines a TFI1 for each dedicatedtransport channel, and a DRNC determines the TFI2 for each sharedtransport channel. The base station maps the TFI1 information for alldedicated transport channels (if any) to a TFCI1. Similarly, the basestation maps the TFI2 information for other shared transport channels(if any) to a TFCI2. If there is only one dedicated transport channeland one shared transport channel, the TFCI1 corresponds to one TFI1value, and the TFCI2 corresponds to one TFI2 value. Both the TFCI1 andthe TFCI2 are provided to the UE terminal by the BS on a dedicatedphysical radio channel.

After receiving the TFCI1 control information over the dedicatedphysical control channel, the UE terminal knows how the differenttransport channels are multiplexed onto the dedicated physical radiochannel. The UE is also aware of the downlink physical channelresources, (e.g., spreading factor, channelization code, etc.), that areallocated when the radio link is first set up. With this information,the UE terminal can receive and demodulate information transmitted overthe dedicated radio channel.

On the other hand, a shared radio channel may use one of several radioresources, (e.g., one of several radio channel WCDMA spreading codes),based on the current radio resource scheduling by the CRNC. Because itis impractical for the UE terminal to know and check for informationregarding all the radio resource(s) currently selected for use by theCRNC, the UE terminal is informed of the currently used radio resourcesfor the shared physical channels, in this example, using the TFCI2control message. The TFCI2 may identify for the UE terminal theparticular radio resources, (e.g., spreading codes), to be used by thecommon/shared physical radio channel at a certain future moment in time.The TFCI2 may also indicate the time or multiplexing position within theidentified frame that corresponds to the information directed to themobile unit which should be decoded.

Typically, the TFCI 1 and TFCI 2 information is an index to a look-uptable provided to and stored in the mobile radio unit during the timethat a connection is established between a core network and the mobileunit. Information in the look-up table includes individually addressableentries of radio resource identification, e.g., a channelization codeand corresponding spreading factor, as well as multiplexing or timinginformation that identify which portions of a particular frame on theshared radio channel contain information for the particular mobile radiounit. The TFCI index is used to address that look-up table and retrievethe corresponding information used by the mobile radio to then receiveand properly decode information intended for it from the shared radiochannel.

A description of TFIs and TFCIs may be found in the 3GPP RAN2specification entitled “Service Provided by the Physical Layer,” 25.302,revision v.3.3.0, incorporated herein by reference. FIG. 2 shows anexample TFI message format in a signaling control frame. An eight bitfield indicates a connection frame number (CFN) followed by a TFI orTFCI indicator. The TFI and/or TFCI may be used to address controlinformation previously stored in a look-up table in the mobile radio asdescribed above. This reduces the amount of data to be transmit over theradio interface. Of course, control information could be communicateddirectly rather than indirectly. Optional Spare and Spare Extension bitfields are also shown.

One approach for communicating TFCI2 information is for the DRNC toinsert the TFCI2 into the information stream to be transmitted on thededicated physical radio channel. The BS then transmits both the TFCI1and TFCI2 on the dedicated radio physical channel over the radiointerface. FIG. 3 illustrates this approach. The scheduled data and theTFI1 control information to be transported on a dedicated physicaltraffic radio channel are received at the DRNC on a correspondingtransport bearer. See the solid line in the transport bearer (shown as atube) between the SRNC 14 and DRNC16. The DRNC inserts the TFCI2 intothat information stream before it is forwarded to the BS via the sametransport bearer (shown as a dashed line in a tube) between DRNC 16 andBS2 20. This approach for conveying the TFCI2 data, however, has somedrawbacks.

First, insertion of the TFCI2 by the DRNC is inconsistent with a RANarchitecture in which control and traffic information related to adedicated physical channel are transported between SRNC and BS by“transparently” passing through the DRNC. If the DRNC must insert theTFCI2, it is no longer transparent. Instead, the DRNC must beknowledgeable of the data content it receives and forwards, whichincreases the complexity of and the delay caused by the DRNC.

Second, if the TFCI2 information arrives too late at the BS, the BS willsend a timing adjustment request in the uplink direction to the RNC. Alluplink information from the BS related to dedicated physical channels issupposed to be passed transparently to the SRNC. Accordingly, the timingadjustment request is transparently passed from the BS by the DRNC tothe SRNC. However, it is the DRNC—not the SRNC—that should perform thetiming adjustment function. The DRNC adds the TFCI2 to the downlinkinformation stream to be transported over the dedicated physical radiochannel.

Third, insertion of the TFCI2 by the DRNC handicaps potential changes tothe RAN configuration. One such change envisioned by the inventors ofthe present invention is described further below in conjunction withFIG. 7. That change includes establishing a direct transport bearerbetween the SRNC and a BS for transporting information related to adedicated physical channel. Although such a direct transport bearer mayhave some disadvantages, (e.g., combining/splitting are not possible inthe DRNC if needed), the benefits of such a solution may outweigh thedrawbacks. Example benefits might include a decreased load on the DRNCand a decreased transport delay on the dedicated physical channel in theRAN, i.e., no DRNC processing and buffering delay. In any event, thisapproach eliminates the need to include the DRNC in the transport bearerroute for data to be transported on a dedicated physical radio channel.

To overcome these drawbacks and limitations, (and perhaps others), thepresent invention employs a separate transport bearer between acontrolling-RNC (CRNC) and a BS to transport CRNC-originated controlinformation that is to be transmitted by the BS to the mobile terminalon a dedicated physical radio channel. FIG. 4 illustrates an example ofsuch a separate transport bearer (the thick dashed line) between a DRNC(the controlling RNC for BS2) and BS2 that conveys such information,e.g., TFCI2 control information originated in the DRNC. Although notshown, in a configuration that includes only an SRNC and a base station,(i.e., there is no DRNC supporting the connection), it may beappropriate or otherwise desirable to establish a separate transportbearer to carry the control information such as TFI informationgenerated by the SRNC.

Although the invention may transmit various types of control informationover the separate transport bearer, the non-limiting, example describedhereafter is TFCI2 control information. Rather than inserting the TFCI2(or other control information) into the information stream related tothe dedicated physical channels, a separate transport bearer isestablished from the DRNC to the BS (the thick dashed line) to conveythe control information, e.g., the TFIC2.

There are three transport bearers established between the DRNC 16 andthe base station 20. A first transport bearer carries to the DRNCscheduled data to be transported on a shared radio channel, like theDSCH. A second transport bearer transports the SRNC-scheduled data to betransported on a dedicated radio channel, such as the DCH, along withcontrol information originated at the SRNC, such as the TFI1. The thirdtransport bearer transports the control information originated at theDRNC 16, which in this case, is the TFCI2.

A Transport Information procedure (block 100) is now described inconjunction with the flowchart illustrated in FIG. 5. A transport bearerrequest is received at the RAN to establish a transport bearer between aparticular UE mobile radio and a core network (block 102). A decision ismade (block 104) whether the UE is in the cell under the control of thedrift RNC. Of course, the connection is initially established by way ofa serving RNC and a base station cell under the control of that servingRNC. However, through movement of the UE during the lifetime of theconnection, it may be handed over to a cell under the control of a driftRNC.

If there has been no handover to a DRNC cell, the SRNC schedules userdata for transmission over a dedicated radio channel and a shared radiochannel, e.g., DCH and DSCH, respectively (block 106). The shared radiochannel handles transmission of bursty traffic (like WWW data) sent toUEs more efficiently than a dedicated channel. The SRNC establishes atransport bearer to transport the DCH data as weil as controlinformation for the DCH and possibly also the DSCH, e.g., TFI1 and TFI2(block 108). The SRNC also establishes a transport bearer to transportthe DSCH data (and possibly some control information) (block 110).

If the UE is in a cell under the control of a drift RNC (DRNC), the SRNCschedules the DCH data and the DRNC schedules the DSCH data (block 112).The DRNC establishes a separate transport bearer between the DRNC andthe base station to convey DRNC-originated control information (e.g.,TFCI2) (block 114). Other transport bearers are established between theDRNC and base station to transport DCH and DSCH information (block 116).

This example implementation of the present invention can be furtherimplemented using appropriate signaling between the SRNC, DRNC, and basestation (sometimes referred to as “node B”). FIG. 6 illustrates anexample signaling diagram. The SRNC communicates with the DRNC using aRadio Network Subsystem Application Protocol (RNSAP). The DRNCcommunicates with the base station (node B) using a Node B ApplicationProtocol (NBAP). An ALCAP protocol is used to establish transportbearers in the RAN.

An RL_SETUP_REQUEST message is sent from the SRNC to the DRNC along witha specific request for a DCH transport bearer and a DSCH transportbearer. The DRNC sends a corresponding message RL_SETUP_REQUEST to thebase station node B and includes a TFIC2 transport bearer request alongwith the DCH and DSCH transport bearer requests. The base stationreturns an RL_SETUP_RESPONSE message to the DRNC and includes DCH, DSCH,and TFCI2 transport bearer parameters, e.g., transport layer addresses,binding identifiers, etc. The DRNC sends an RL_SETUP_RESPONSE message tothe SRNC including the DCH and DSCH transport bearer parameters.Accordingly, DCH and DSCH transport bearers are established between theSRNC and DRNC using ALCAP signaling. DCH, DSCH, and TFCI2 transportbearers are established between the DRNC and the base station node Balso using ALCAP signaling.

FIG. 7 illustrates another non-limiting, example RAN implementationwhere data to be transmitted on a dedicated physical radio channel istransported in the RAN directly from the SRNC to the BS, along with anyassociated control information, e.g., the TFCI1. In FIG. 7, however, thedirect transport bearer between the SRNC and the BS to transportdedicated physical channel information eliminates the need to relay thisinformation through the DRNC. By not routing the transport bearerthrough an intermediate DRNC node, internal RAN transport delay isdecreased. Thus, BS2 receives the TFI1 information directly from theSRNC. However, because a separate transport bearer is establishedbetween the DRNC and BS2 to carry DRNC-originated control informationrelating to the DSCH data, the TFCI2 control information may also becommunicated to BS.

A separate control information transport bearer does not need to be usedin all situations. If the CRNC corresponds to the SRNC, theCRNC-originated control information to be transmitted on a dedicatedphysical channel over the radio interface may be multiplexed on thedirect Iub transport bearer from the SRNC to the BS along with thededicated physical channel information. A separate transport bearercould also be used. If the CRNC is a DRNC tasked with transmittingnon-scheduled data via a shared physical channel, and with generatingcontrol information to be transmitted on the dedicated physical channelsover the radio interface, the DNRC establishes a separate transportbearer to transport DRNC-originated control information. Consequently,control information originated by the DRNC is simply sent by way of theseparate transport bearer. Data received from the SRNC is quickly andtransparently passed through the DRNC to the base station. In addition,the DRNC, and not the SRNC, is able to perform any timing adjustmentfunctions required by the base station for data which is scheduled bythe DRNC. Also, the invention allows flexibility with potential changesto the RAN configuration, an example of which was just described abovein conjunction with FIG. 7. Namely, the dedicated channel data can godirectly from the SRNC to the base station even though the sharedchannel scheduling is done in the CRNC. This configuration reducesdelays in handling of dedicated channel data.

While the present invention has been described with respect to aparticular embodiment, those skilled in the art will recognize that thepresent invention is not limited to the specific example embodimentsdescribed and illustrated herein. Again, the invention is not limited tothe TFI and/or TFCI examples provided above. Different formats,embodiments, and adaptations besides those shown and described as wellas many modifications, variations, and equivalent arrangements may alsobe used to implement the invention.

1-40. (canceled)
 41. A computer-generated data signal embodied in anelectrical signal transported on a radio access network (RAN) transportbearer established between a first RAN node corresponding to a driftradio network (DRNC) coupled to a serving radio network controller(SRNC) controller and a second RAN node corresponding to a base station,where the base stations communicates via a radio channel with one ormore mobile radio units, comprising: a frame number field including aspecific frame number corresponding to a frame on the radio channel, anda transport format field including information relating to a particularradio channel resource useable by a mobile radio unit to receiveinformation directed to the mobile radio unit from the base station. 42.The computer-generated data signal in claim 41, wherein the transportformat field includes information that may be used to address atransport format table stored in a mobile radio unit.
 43. Thecomputer-generated data signal in claim 41, wherein the transport formatfield contains information that may be used by a mobile radio unit toreceive information intended for the mobile radio unit carried on ashared radio channel.
 44. The computer-generated data signal in claim41, wherein the transport format field includes a transport formatcombination indicator (TFCI) generated by the drift radio networkcontroller.